Road tamping and maintenance machine



" May 13, 1930. w. w. FOST 4 1,758,281

ROAD TAMPING AND MAINTENANCE MACHINE Filed May 11, 1928 4 Sheets-Sheet 114/9 5167 .FO/GM' INVEN TOR.

ATTORNEY.

May 13, 1930.

w. w. FOSTER ROAD TAMPING AND MAINTENANCE HACHINj Filed May 11, 1928 4Sheets-Sheet 2 v E Q-\ R} M Q R wmm 3 Q i :z m 5' 5Q a l I Q; 4 K J J Jg R w 0 v 00 LA) 2 o s 0 0 Q D 3 \1 l jf filli ia'ster INVENTOR.

ATTORNEY. i

May 13, 1930. w. w. FOSTER ROAD TAMPING AND MAINTENANCE MACHINE FiledMay 11, 1928 4 Sheets-Sheet 3 INVENTOR.

May 13, 1930. w. w. FOSTER ROAD TAMPING AND MAINTENANCE MACHINE FiledMay 11, 1928 4 Sheets-Sheet 4 ATTORNEY.

Patented May 13, 1930 OFFICE WALTER w. FOSTER, or WIGHITA- FALLS, rEXAsROAD 'rAMrinG AND MAINTENANCE MAGHINE j Application filed May 11,

This invention relates to certain new and useful improvements in roadand highway maintenance apparatus and it refers more particularly to amachine as specified, having for its principal object the provisionof'a' machinefor preparing a permanent road bed either for surfacingwith some form of road construction material, or may itself be used as afinished highway due to the manner in which the soil is tamped andpacked by the machine. v f

Another object of theinvention're'sides in the provision of a machine asset forth in the foregoing, provided with a t-amping bar of such weightas to strike the earth with terrific force, and its weight, combinedwith the added impetus giventhe bar by suitable machinery forso'bringingthe bar against the earth, is such as-rto thoroughly and firmly 39 packthe earth and thus create a foundation of permanence for a road orhighway. I

Still another object of the invention resides in the provision of atampingbar capable of operatively spanning half the width of the averageroad or highway, and soarranged', as is the means of operating thebar',to be moved progressivelyalong such road or high way, the bar strikingthe earth successive blows as the machine islmoving, thus enabling theapparatus to cover a considerable area of road with effectiveness. 7'The invention further aims among its objects to provide an engine, and ameansiof distributing the power thereof to operate the said tamping barand to move said apparatus from place toplace. I a f A particularlyimportant object of the invention resides in the provision of anauxiliary tamping member with which said tamping bar co-operates, thefunction of which is to insure uniformity in the surface prepared bysaid tamping bar, by becoming operative only when said ba'r impinges" acomparatively soft portion of soil or enters a depression in the earthand sinks below the normal plane, whereupon said auxiliary tampingmember is engaged by a portion of said bar and is brought against theearth with equal force equal tothat of said bar.

With the foregoing objects as paramount,

1928. Serial No. 276,825.

the invention has particular reference to' its salientfeatures ofconstruction and operation of parts to become manifest a'sthe'description proceeds, taken in connection with the accompanyingdrawings, 'wherein:"

' Figure 1 represents a side elevational view of a road tamping machineconstructed according to the invention.

Figure 2 is a side elev'ational' viewin verticals'ection.

V Figure 3 is an end elevation thereof.

Figure l is a detail view of thec'o-operating relationship between thetamping bar and the auxiliary tamping member, on lines 44 of-Fi gure 3,:and

Figure 5 is a planview' of the apparatus. In continuing further inmore-detail, it may be here stated that inthe present day constructionof roads, and highways as well as rail roads, the foundationmust ofnecessity be-buil-t with a view of permanence ,1 clue especially to thelieavytraific to which the roads are subjected, and unless an extremelyhard and durable bed or foundation is pre- 1 pared, the surface islikely to crack and deterior'ate under the severe treatmentsubjectedwthereto by heavy loads drawn theredations for roads andhighways, it is; essentialthat a'reasonably firm" surface be first prepared to insure uniformitybefore pouring the, concrete,- to preventcracking thereof after setting. g V v 1 Accordingly; thepresent-invention comprehends the provision ofra machine havingfacilities by, which it is possibleto thoroughly pack and tamp the earthpreparatoryito constructing a road or highway, or in-lev-el-ing highpoints in much used gravel and other roads,: and even in preparing roadbeds in the construction ofrail roads:

In the drawings, 1' designates preferably a channeliron chassis, theforward portion of which is mounted uponthe usual truck wheelsZQ, havingatruck difierential 3 of preferably worm dr ives. Arranged near the rearof the 'chassisl is" a single wheel a, which, as shown; in Figure 2, isadapted to swivel to provide means by which the machine may beguided';This wheel is mountover. Even in the laying of concrete foun- V edin afork supported by a channel iron arch 6 by means of a bearing 7 aflixedto said arch and embracing the spindle 8 extending upwardly from thefork 5 and through the top of-the arch and upon whichis mount- 1 ed acollar 9.

The steering mechanism consists of a, worm gear 10, rigidly mounted onthe splndle 8, cooperating with which 1s a worm 11 mounted upon the endof'the steering rod 12, wh ch carries upon its opposite end the steeringWheel 13. It will be observed that the steering rod 12 is braced by'suitablebearings 14 af-' fixed to the arch 6 and uprights 15 formlngpart of the upper frame and of which the overhead beams 16 form acontinuatlonr The said beams 16, as apparent in the figuresextend at anangle to the forwardend of the machine at which point they are afiixedto uprights 17 mounted upon the chass s 1. Due to the great strain andvlbrat on to which the machine issubjeeted in operation, the frame mustofv necessity be constructed with a view of great strength andendurance. Forwardly of the foremost uprights 17 is mounted theg'uidelframe of the tamping bar 18 shownin detail section 'in Figure 4:

and illustrated in its position relative to other elements of theassembly. in Figures 1 and 2.

This guide frame, it is important to' note is so arranged relative'toand connected with the chassis 1 of the machine so as to be capable ofadjusting itself to the ground surface irrespective of the position ofthe chassis,

, that is to say, the frame is arranged to, at all times, when themachine is in operation, be

at right angles to the ground surface to enable 24 beneath the base bar25 of the frame 19, which latter overreaches the sides of the ma chinechassis by considerable margin; A s1milar bar26 is provided at the frontof the guide frame and it is to this latter bar that the frame 20 isconnected. In further support of'the guide frame assembly, in event adepression in the earth is encountered, a structure 27 protrudes fromthe machme frame 16 at the top, the lateral port-ion thereof embracingthe front of the outer frame 20,

to hold the guide frame assembly against an inclination to lean awayfrom the machine frame. 'As shown particularly in Figures 1 and 5, acleat 28 is affixed to either side of the frame 19 of the tamping barguide frame assembly, and which embraces, in the manner shown in Figure5, the uprights 17 of the machine frame.- These cleats are "so arrangedas to allow for a considerable amount of universal play between theguide frame and the machine frame proper during operation of themachine. Intermediate the inner and outer frames 19 and 20 respectivelyis situated a vertical member 29 supporting bearings 30 in which theends of shafts 31 are disposed, the other ends of these shafts aresupported by bearings 30 mounted oppositely in outer frame 20. Theserollers have preferably a surface covered by some form of elastic oryieldable material such as rubber or fiber, the purpose of'which willbe'later made clear.

Intermediate the said member 29 and outer guide frame 20'is situated forindependent vertical movement the tamping bar frame composed of verticalmembers 33, joined together at their tops by head piece 34, and rigidlyconnected to the tamping bar.

As mentioned previously, the lateralbar 25 overreaches the side of themachine chassis '1, as does the forward bar 26, to which the outer guideframe 20 is secured, and intermediate these frames 19 and 20, thetamping bar 18 is, operative and is also of such length as toextend-well beyond the sides of the machine chassis, as may be seen inboth Figures3 and 5'. In so extending the elements constituting'thetamping assembly, a greater operative area is had, and it is the purposeto afford an area of sufficient width as to cover half of the averageroad bed. However, in so'extendingthe operative area, suit-' ablesupports must be provided to stabilize the outer ends of the elementscomposing the tamping bar guide frame as well as the tamplng bar itself.Such supporting means is preferably in the form of angular braces 35extending from the outer ends of bar 25 upward to the top of the innerguide frame 19; similar braces 36, extending from the outer endsof thetamping bar 18 to the top of the tamp ng bar frame 33, and braces 37arrangedm a similar manner for supporting the outer ends of the outer,bar 26 relative to the outer guide frame 20. Due to theenormous weightand the obvious strain upon the tamping bar frame 33, a greater numberof such braces are prov ded to support the bar 18 relative to saidframe, and as shown in Figure 3, bear the same character of reference,36.

It is now obvious from the foregoing, that the tamp ng bar guide frameassembly, composed of inner'and outer frames 19 and 20', respect velyand their associated elements, is

capable of comparatively free movement relative to the machine chassisas hereinbefore. mentioned, to adjust itself to the'function andv variedpositions of. the tamping bar proper duringoperation thereof. Theassembly, during such operation of the tamping bar however, normallyrests upon the rollers 23- affixed to the bar 25. Consequently, in eventof lateral side swing of the bar the greater pressure will be'imposedupon one or the other of these rollers.

In Figure 3 especially, it will be noted that gaged by the rollers 32arranged in spaced relationship intermediate the inner andouter guideframes 19 and 20. Thus, frictional wear upon the tampin'g "barframe ismini-' mized, and further, such an arrangement affords greater freedomof movement of the frame in its vertical travel.

Referring again toFigures 1 and 2 especially, a working beam 38 ismounted atone end upon a lateral shaft 39, in turn mounted in bearings40 affixed to uprights 15 supporting the upper machine frame 16; Thisbeam extends forwardly of the machine and between the uprights of the.guide frame as-. sembly, as particularly shown in the front.

elevational view in Figure 3., The forward or operative end of the beam38 is slotted as shown and has bearings 41 mounted to oppose said slot,and which bearings receive the lateral pins 42 of a collar 43. Thiscollar is freely slidable on a lift rod 44, vertically arranged relativeto the tamping bar 18 and affixed thereto in the manner shown in Figures2 and 3, in providing. a ball housing or socket encasing a ball fixed tothe end of the rod 44,. thus providing a universal jointbetween the liftrod and tamping bar. r v The collar 43 is opposed on the lift rod 44 bycompression springs 46 as-shown, which latter are constrained againstmovement or displacement by stop collars 47 This arrangement affordsa'means for absorbing, the shock created by the obvious force in whichthe tamping bar 18 is brought into contact with the earth,.and toprevent jarring othe than the bar 18 and its frame. .7

The machinery for actuating the beam 38 and consequently the tamping baris better illustrated in Figures 2 and 5. A motor 48 is provided, ofsuitable horsepower, and is of r the type having an auxiliarypowertake-oif unit, which, in the drawing, Fi ure 5, is designated at49. It is obvious that greater power is required to operate the tampingbar than is required to propel the machine, hence, the engine 48 isoffset inthe manner shown order to bring the power take-off shaft intoalinement with the propeller shaft 50 of. the machine, thereby to drivethe difierential 3 from the power take-ofi unit to propel the wheels 2,while the transmission of the engine 48 is brought to one side fromwhich the shaft 51 is driven which shaft operates the working beam 38ently described.

Arranged oppositely upon the chassis 1 of the machine is a pair ofstandards 52, supporting a lateral crank shaft 53, and tothe crank 54thereon is mounted the end of a conin the manner. to be pres- 'nectingrod 55, the other end of which is congear 56 is mounted thereon as shownin Figures 2 and 5, co-op'erating withwhich is a worm 57 mounted onshaft 51 from the engine 48. Hence, all of the speeds of the engine maybe transmitted to either the working beam 38 or to the wheels 2 tooperate the said In driving the crank shaft 53, a large worm tamping barduring movement of they machine along the road. v

Reference now'is made to Figure 4 wherein is shown a sectional detailview of the tamping bar 18 and associated elements on line 44 'of'Figure 3. An auxiliary tamping member 58 is provided, and is adapted tocooperate, or be operated by the tamping bar 18, in event the latter,when operating in relatively soft ground, sinks below its normal limitof travel, determined by the compactness of the earth. I

This member 58 is suspended by bolt 59,

v yieldingly held relative to. a projection integral with the inner bar25 of the guide frame, by a compression spring 61. A shoulder 62,longitudinally arranged on the tamping bar, is adapted to contact with.the auxiliary tamping member 58 and carry the same downward against theearth against the tension of spring 61. A layer of compressible material63 is appliedto the striking face of.

the auxiliarytamping member 58 as shown in Figures 2ancl 4 to preventundue wear and possible injury to either of the tamping members'18 and58 by the forceful contact of th shoulder 65'against said member 58.

The member 58, after having been driven down by the bar 18, recedes tonormal inoperative position as shown in Figure 4, by the action. ofspring 61, until such time as the bar 18 again strikes soft soil,whereupon the shoulder is brought into contact with the member 58 and itis again brought. forcefully down against the earth.

In normal operation of. the machine, the

rollers 23 supporting'the guide frame roll upon the ground, but in eventit-is desired to transport themachine from place to place withrelatively increased speed, it is desirable that the entire guide framebe elevated to a higher position to lift the rollers 23 oil the ground.This is accomplished by providing a shaft arranged laterally across theuprights 17 at the forward end of the machine and-mounting on said shafta winch 65. a

cable 66 is arranged'on this winch and is connected, as shown in Figure2 exclusively, at a to the lower partof the inner frame 19 of the guideframe assembly. A ratchet lever 68, shown in Figure. 1 is arranged torotate the winch 65 towind the cable 66 therearound andthus. elevate theguide frame as sembly, It has not been considered necessary to go intogreat detail regarding the elevating means, since such means is old inthe art, and in. the present case consists simply of a conventional typeof winch and ratchet and pawl mechanism. 7 It will be observedin Figure5, a plan view, that extensions 69 areappliedto the brake andfclutchpedals 0f the engine 48 in order that the operator may convenientlyoperate the engine and at the same time observe the work of the machine.It is of courseunderstood that this featureas well as other features ofthe invention may be changed from time to time as is consideredpracticable for the, further development of the'machine.

In operation, the machine isdriven down a road slowly and the tampingbar 18 put into operation to reciprocate against the earth, its speedbeing governed according to the speed at which the machine is moving. Itis possible to reciprocate the bar at a speed of approximatelyrevolutions. per minute without any loss in its efiectiveness at lessspeed,

consequently it is obviously possible to cover a considerable area in avery short period of time as compared with other maintenance machines. a

In road maintenance work, that is, roads over which the passage ofvehicles-have made the surface irregular and difiicult to traverse incomfort, the present invention is valuable in reducing the high pointsto a uniform level surface of comparative permanence, due to thecompressed c0nd1t1on of the soil or material after having passed themachinethereover.

I claim V 1. A machine and apparatus of the character describedincluding a wheeled frame and'a tamping bar arranged at the end of saidframe for vertical reciprocation; means for operating said bar, anauxiliary tamping member co operating with. said bar, and adapted to beoperated thereby when'the latter'moves beyond its normal limit oftravel. '2. A machine ofthe character described including a wheeledframe; and a means for propelling the same; a tamping 7 bar arrangedin-said frame and adapted to be forcibly brought against the earthsuccessive 1y; means for transmitting operating power to said tampingbar from said. propelling means, and means adjacent said tamping bar andadapted to be operated thereby. to maintain uniformity of surface tampedby said bar when the consistency of said surface per- ,mits the latterto .move beyond its normal said machine propelling means, and means 00-7 operating with said bar to 'maintain uniformityof the surface tampedby said bar.

4. A machine for leveling and tamping roads havingja weighted tampingelement mounted in a frame and operating perpenforcible contact with theearth as saidmachine is transported thereover, an auxiliary tampingmember arranged to be engaged'by said element when this latter hasdescended a thereby into forciblecont-act with said road 3 surface whensaid tamping element is urged below its limit of travel.

7. A road building and maintenance ma chine having atamping elementarranged for reciprocation in a frame vertically with respect to thesurface being tamped, an auxiliary tamping element arranged in parallelrelationship with said first element and capable of being brought intoforcible contact with said road surfacewhen said'first element is urgedI beyond its normal limit of travel, means for operating said elements,

means to cushion the shockcreated by impact of said elements with saidsurface, with're spect to said element operatlng means.

8. A road building and maintenance machine including a wheeled frame anda tamping element arranged to reciprocate vertically with respect. tosaid road; a guide frame therefor; an auxiliary tamping member relativeto said tamping element andadapted to be operated by said tampingelement, yieldable means for holdingsaid aux iliary tamping member ininoperative posi-- tion relative to said guide frame and tampingelement, said means also arranged to relieve said guide frame of theshock created' by impact of said tamping element with said auxiliarytamping member, and means to elevate saidguide frame, tamping elementand auxiliary tamping element. 7

In testimony whereof I affix' my signature.

' WALTER W. FOSTER.

